Inertial sensor and electrical or electronic device

Abstract

An inertial sensor includes an oscillator that is supported by an elastic supporting member such that the oscillator is floating relative to a base and the oscillator is displaceable along a single axis, and a displacement detection unit detecting a displacement of the oscillator. The oscillation of the oscillator is a simple harmonic motion along a Z axis. An X axis, a Y axis, and the Z axis, serving as reference axes of an oscillation coordinate system for the oscillator, are shifted to provide x, y, and z axes, serving as new reference axes. Position coordinates of the oscillator of the x, y, and z axes are determined in at least two points during one period of the oscillator. A difference vector (Δx, Δy, Δz) is calculated on the basis of the determined position coordinates. An angular velocity or an acceleration is obtained using the difference vector.

1. An inertial sensor comprising:
 an oscillator that is supported by an elastic supporting member such that the oscillator is floating relative to a base and the oscillator is displaceable along a single axis; and 
 a displacement detection unit that detects a displacement of the oscillator, 
 wherein,
 an oscillation of the oscillator is a simple harmonic motion along a Z axis, 
 an X axis, a Y axis, and the Z axis of a rectangular coordinate system, serving as reference axes of an oscillation coordinate system for the oscillator, are shifted to provide an x axis, a y axis, and a z axis, serving as reference axes of a new oscillation coordinate system, 
 position coordinates of the oscillator of the x, y, and z axes are determined at at least two points during one period of the oscillator, 
 a difference vector (Δx, Δy, Δz) is calculated on the basis of the position coordinates of the x, y, and z axes determined at the two points, and 
 an angular velocity or an acceleration is obtained using the difference vector. 
 
 
     
     
       2. The inertial sensor according to  claim 1 , wherein the x, y, and z axes, serving as the new reference axes, are obtained by shifting the X, Y, and Z axes by an angle α, an angle β, and an angle θ, respectively, the X, Y, and Z axes serving as the reference axes for detection of the oscillation direction of the oscillator. 
     
     
       3. The inertial sensor according to  claim 1 , wherein the x, y, and z axes form a rectangular coordinate system. 
     
     
       4. The inertial sensor according to  claim 1 , wherein the z axis is arranged so as to pass through the coordinates (1, 1, 1) of the X, Y, and Z axes in the rectangular coordinate system. 
     
     
       5. An electrical or electronic device comprising:
 an inertial sensor that measures an angular velocity or an acceleration caused by the motion of the electrical or electronic device, 
 wherein,
 the inertial sensor includes (a) an oscillator that is supported by an elastic supporting member such that the oscillator is floating relative to a base and the oscillator is displaceable along a single axis, and (b) a displacement detection unit that detects a displacement of the oscillator, 
 an oscillation of the oscillator is a simple harmonic motion along a Z axis, 
 an X axis, a Y axis, and the Z axis of a rectangular coordinate system, serving as reference axes of an oscillation coordinate system for the oscillator, are shifted to provide an x axis, a y axis, and a z axis, serving as reference axes of a new oscillation coordinate system, 
 position coordinates of the oscillator of the x, y, and z axes are determined at least two points during one period of the oscillator, 
 a difference vector (Δx, Δy, Δz) is calculated on the basis of the position coordinates of the x, y, and z axes determined at the two points, and 
 an angular velocity or an acceleration is obtained using the difference vector.